Histological Preparation Technique of Blood Derivative Injectable Platelet-Rich Fibrin (I-Prf) for Microscopic Analyzes

Objective: The objective of the present study was to describe the histological preparation technique of blood derivative injectable platelet-rich fibrin (i-PRF) for microscopic analyzes. Materials and methods: Blood samples were collected from 15 volunteers to prepare i-PRF samples. The difference between i-PRF and oral mucosa tissue experimental protocol for histological preparation was elaborated in Step 1 - fixation, with 01 hour for i-PRF fixation and 24 hours for oral mucosa tissue. The other histological preparation protocol steps used for the processing and staining of the specimens were similar to that used for oral mucosa tissue. Tissue and i-PRF samples were analyzed by immunofluorescence, immunohistochemistry and microscopic histology. Results: In comparing i-PRF and oral mucosal tissue, it was observed that both had similarities in morphology and coloration of the visualized structures. The technique demonstrates immunostaining regulation of TGF-β from i- PRF. VEGF was fully detectable using the immunofluorescence technique applied to i-PRF. The method showed a fundamental advantage in reducing the fixation time, since the established fixation time in oral mucosa tissue is at least 24 hours. For the i-PRF, it was observed that the fixation was 01 hour, so the reduced fixation time shows an advantage in reducing the total working time without compromising the quality of the analyzed samples. Conclusions: The method showed a distinct advantage in reducing the fixation time of i-PRF. These initial analyses revealed that the slow polymerization during i-PRF preparation generates a blood derivative with a special fibrin network rich in platelets and leukocytes, and the presence of immunostaining for TGF-β and immunofluorescence of VEGF.